Bis(trihydrocarbyl tin oxy) aromatic biocide



United States Patent 3,236,727 BISGREHYDROCAREYL TIN OXY) AROMATIC BlilClDE Gustav Weissenherger, Zurich, Switzerland, assignor to Monsanto Company, a corporation of Delaware No Drawing. Qriginal application Jan. 2, 1962, Ser.

No. 163,900, now Patent No. 3,129,236, dated Apr. 14, 1964. Divided and this application Sept. 6, 1963,

Ser. No. 311,274 Claims priority, application Switzerland, Dec. 31, 1960, 14,662/60 4 Claims. (Cl. 16730) This application is a division of copending application Serial No. 163,900, filed January 2, 1962, now US. Patent No. 3,129,236.

The present invention relates to new and useful organic tin compounds, a method of making these compounds, biological toxicant compositions and the use of these compounds as biological toxicants. These new compounds are of the general formula In this formula R, R and R" signify identical or different aliphatic, araliphatic, cycloaliphatic, or aromatic hydrocarbon radicals, X is an aromatic, possibly halogen-containing hydrocarbon radical, or aromatic, possibly halogen-containing hydrocarbon radicals which are connected directly to one another or are connected by an aliphatic, araliphatic or cycloali-phatic hydrocarbon radical. The radicals attached to the tin atom as well as the radicals joining the phenols may be unsaturated. Y is a hydrogen atom, a metal atom, preferably alkali metal atom, or another tin group RR'RSn. The preferred new organotin compounds of the invention are those having not more than 18 carbon atoms in R, R or R"; however, for some uses organotin compounds are preferred wherein R, R or R have not more than 8 carbon atoms.

These organotin-bis-phenolates which have been unknown until now, can be obtained in different Ways. In a generally preferred method a triorganotin oxide or a triorganotin hydroxide and a bis-phenol are heated together, thereby the water which is formed. by the reaction is continuously removed from the reaction mixture, as by evaporation, possibly under reduced pressure, or in an azeotrope with a solvent such as, for example, benzene, toluene, xylene, cyclohexane, etc. However, water-binding agents may also be used for this purpose. The condensation occurs according to the equation:

In another method a triorganotin halide is reacted with a monoor dialkali salt of a bis-phenol, or with a bis-phenol in the presence of an acid-binding agent, preferably in a solvent. The necessary alkali salts can be prepared by methods well known in the art using alkali metals or alkali metal hydrides. Tertiary organic bases such as, for example, triethylamine, pyridine, etc., are advantageously used as acid-binding agents. This reaction proceeds according to the scheme:

Still a further method resides in the reaction of a triorganotin alkoxylate with a bis-phenol, according to the equation:

Lower (not more than 8 carbon atoms) organotin alkoxylates such as methoxylate, ethoxylate, etc., are preferably employed in this transesterification, and the alcohol split off, is distilled. continuously from the reaction mixture which is heated conveniently at about -120 C. Known catalysts promoting the reaction may be present. Depending on the circumstances, it may be advantageous to pass nitrogen into the reaction mixture.

By using the proper stoichiometric ratio of bis-phenol to tin compound reaction only one of the two hydroxyl groups of the bis-phenol reacts with the tin compound. Such compounds are equally useful for the proposed utilization and they have a better solubility, especially when they are in the form of alkali salts. The alkali metal can originate from the reaction, if a dialkali salt of a bisphenol is reacted with half the equimolar amount of a triorganotin chloride. However, in this manner is formed, as a rule, a mixture of unsubstituted, monoand disubstituted bis-phenols or bis-phenol salts. In order to get uniform products, therefore, it is suitable to convert in the usual way, end products which have still a phenolic hydroxyl group, to the desired metal salts, especially alkali salts.

Hemi-esters of bis-phenols may also be obtained on transesterification of bis-triorganotin phenolates by the reaction of bis-phenol at higher temperatures, thereby, sometimes, it may be advantageous to work with catalysts and under exclusion of oxygen. This transesterification occurs according to the equation:

Examples of triorganotin compounds which can be reacted with bis-phenols are trimethyltin oxide, triethyltin oxide, trivinyltin oxide, tri-n-propyltinoxide, tri-iso-propyltin oxide, tripropenyltinoxide, triethynyltin oxide, triallyltin oxide, tri-n-butyltin oxide, trioc-tyltin oxide, trilauryltin oxide, tristearyltin oxide, trioleyltin oxide, tribenzyltin oxide, tristyryltin oxide, tricinnamyltin oxide, triphenyltin oxide, tricyclopentyltin oxide, tricyclohexyltin oxide, tricyclohexenyltin oxide, tricyclohexadienyltin oxide, etc. In place of these, the corresponding halides or the salts of other acids, or, if available, even hydroxides can be used in the reaction. Of course, the three hydrocarbon radicals on the tin atom can also be different, i.e. be a combination of the enumerated radicals. However, the symmetrically substituted triorganotin oxides, chlorides, hydroxides and alkoxides are generally more easily obtained and are therefore, to be preferred.

All existing bis-phenols can be condensed, or reacted or transesterified with these triorganotin compounds to give novel products as defined at the beginning. Preferred bis-phenols are those having not more than 25 carbon atoms.

The phenolic hydroxyl groups may be arranged in the bis-phenols in para, ortho or meta position with respect to one another, or with respect to the ring-connecting hydrocarbon radicals. Moreover, the phenol radicals may be joined either directly, or through a carbon atom, or through a chain of carbon atoms.

Suitable bis-phenols are, for example, bis-hydroxyphenyl, dihydroxybenzenes, naphthalene diols, anthracene diols, bis-(hydroxyphenyD-methanes, -ethanes, -propanes, -butanes, -octanes, -cyclopentanes, -cyclohexanes, -phenylmethanes, -diphenylmethanes, etc.

The aliphatic, araliphatic or cycloaliphatic radicals linking the two phenols can likewise be unsaturated, as in dihydroxystilbenes, bis-(hydroxyphenyl)-propenes, -styrenes, -cyclohexenes, etc.

The corresponding compounds which contain halogenated bis-phenols were found to be particularly effective. A halogenated bis-phenol is understood here to be a bisphenol which contains in the aromatic ring at least one halogen atom, preferably chlorine atom. As a rule, the benzene rings show 1-4 chlorine atoms which may be arranged in the optional possible manner with regard to the phenolic hydroxyl groups. Compounds derived from 2, 2' dihydroxy-5,5'-dichlorodiphenylmethane or 2,2-dihydroxy-3,5,6,3,5,6'-hexachlorodiphenylmethane and corresponding to the formulae.

Cl Cl C1 C1 C1 G1 I l I I I I or 43 l I OSnR: OSnR; Cl OSnRs OSnRa Cl have been found to be particularly active.

The novel compounds serve as bactericide, fungicide, plant protecting agent, herbicides, insecticides, etc. For these purposes, they can be converted to emulsions or mixed with fillers in conventional manner.

EXAMPLE 1 Analysis:

Percent Cale'd. Found EXAMPLE 2 35.7 g. of tributyltin oxide (0.06 mol) and 14.9 g. of tetrachlorohydroquinone (0.06 mol) are refluxed in 230 ml. of benzene and the water formed in the reaction is azeotropically distilled off from the reaction mixture. The reaction is complete after 2 hours. After the benzene has been distilled off a clear liquid product remains, having a refractive index of 11 1.5414.

Analysis:

Percent Calcd Found EXAMPLE 3 By the same process as in Example 2, using 17.9 g. of tributyltin oxide (0.03 mol) and 12.2 g. of 2,2'-dihydroxy-3,5,6,3',5',6' -hexachlorodiphenylmethane, a clear liquid condensation product is obtained quantitatively, having a refractive index of n 1.5638. The amount of water released corresponds to the theory.

Analysis:

Percent Calc'd. Found EXAMPLE 4 By the same process as in Example 2, using 17.9 g. of tributyltin oxide (0.03 mol) and 8.1 g. of 2,2'-dihydroxy- 5,5'-dichlorodiphenylmethane (0.03 mol) in 150 ml. of toluene, a clear liquid condensation product is obtained quantitatively showing a refractive index of n 1.5430. The amount of Water which is split off corresponds to the theory.

EXAMPLE 5 18.3 g. of triphenyltinhydroxide (0.05 mol) and 6.2 g. of tetrachlorohydroquinone (0.025 mol) are refluxed in ml. of benzene or toluene. The water formed is azeotropically distilled off from the reaction mixture. The reaction is complete after l /2-2 hours and the product formed precipitates partly during the condensation. The desired product remains quantitatively upon distillation of the solvent. The substance can be purified by recrystallization from toluene; M.P. 215216 C.

Analysis:

Percent Sn calcd 25.1 Percent Sn found 24.8

EXAMPLE 6 In this example the pre-emergent herbicidal ratings of some of the organotin compounds of this invention were determined in greenhouse tests in which a specific number of seeds of 12 different plants, each representing a principal botanical type, were planted in greenhouse flats. A good grade of top soil was placed in either 9 /2" x 5%" x 2%" or 9" x 13" x 2" aluminum pans and compacted to a depth of /8 inch from the top of the pan. On top of the soil were placed five seeds of each of radish, morning glory, and tomato; 10 seeds of each of sugar beet, sorghum, and brome grass; 20 seeds of each of wild buckwheat, giant foxtail, rye grass, wild oat; approximately 20 to 30 (a volume measure) of each of pigweed and crab grass; and either 2 or 3 seeds of soybean. The seeds were arranged with three soybean seeds across the center of the large aluminum pan, the monocotyledon or grass seeds scattered randomly over the remaining one-third of the soil surface, and the dictoyledon or broadleaf seeds scattered randomly over the remaining one-third of the soil surface at the other end of the pan. The seeds were then covered with inch of prepared soil mixture and the pan leveled. The herbicidal composition was applied to the plantings prior to the watering of the seeds. This application of the herbicidal composition was made by spraying the surface of the soil with an acetone solution containing a suflicient quantity of the candidate chemical to obtain the desired rate per acre on the soil surface. The watering of the seeds was accomplished by placing the aluminum pans in a sand bench having one-half inch depth of water thereon and permitting the soil in the pans to absorb moisture through the perforated bottom of the pans.

The planted pans were thereafter placed on a wet sand bench in a greenhouse and maintained there for 14 days under ordinary conditions of sunlight and watering. At the end of this time, the plants were observed and the results recorded by counting the number of plants of each species which germinated and grew. The herbicidal rating was obtained by means of a fixed scale based on the average percent germination of each seed lot. The herbicidal ratings are defined as follows:

0 No phytotoxicity,

1 Slight phytotoxicity.

2 Moderate phytotoxicity. 3 Severe phytotoxicity.

5 The pro-emergent herbicidal activity of some of the organotin compounds of this invention are recorded in Table 1 for various application rates of the organotin 6 was a mixture comprising 35 wt. percent butylamine dodecylbenzene sulfonate and 65 wt. percent of a tall oil-ethylene oxide condensate having about 6 moles of Table 2 Compound Plant Type The product of Cone, wt. percent A B C D E F G H I .T K L M N Example 1 0.2 1 4 3 1 1 1 4 4 2 2 4 4 4 4 1 0. 05 0 2 0 0 0 0 4 O 0 0 4 0 4 0 0 0. D1 0 0 0 0 0 0 0 0 0 0 0 0 O 0 0 Example 2 0.2 0 4 3 l 0 0 4 4 1 l 4 4 4 4 0 0.05 0 0 0 0 0 0 3 0 0 0 0 0 0 O 0 0.01 O 1 l Example 3 0.2 1 3 2 1 1 0 4 1 1 l 4 2 3 4 0.05 1 1 Example 4 0.5 2 4 2 1 1 0 4 1 2 2 4 4 3 4 3 0.2 0 2B 0 1 1 0 4 0 1 1 4 2 0 4 0 0.05 0 1B 0 0 0 0 3 0 0 0 0 1 2 0 0 B =26-50% defoliation.

compounds. In Table l, the various seeds are represented by letters as follows:

ethylene oxide per mole of tall oil. The injuries to the plants were then observed 14 days later and are reported A G l grass, in Table 2. The herbicidal ratings recorded in Table B G l b dl fl 2 have the same meaning as stated in Example 6. C Mornin glory, The herbicidal compositions of this invention are either D Wild t particulate solid (i.e., dusts) or liquid concentrate com- E Br m grass, positions comprising the active ingredient and either a F Rye grass, particulate solid or liquid herbicidal adjuvant which are G R di h formulation aids or conditioning agents permitting the 1-1 Sugar b t, concentrate composition to be readily mixed with a suit- I F t iL able solid or liquid carrier in the field for application of J C b grass the active ingredient on soil or plant surfaces in a toxic K Pi d, c ncentration in a form which enables prompt assimila- L Soybea tion by the germinating seeds, emerging seedlings, or M Wild b k heat 5 full grown plants. Thus, the herbicidal compositions of N T t this invention include not only the concentrate composi- S h tions comprising the active ingredient and the herbicidal Table 1 Compound Plant type The product ot Rate,1bs./acre C D E F G H i I i J l K L M N 0 --t 0.5 0000000000000 Example2 5 01203223 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 --t tttttttiastts 0.5 0000000000000 The data in Table 1 illustrates the general herbicidal adjuvant but also herbicidal toxicant compositions apactivity as well as the selective herbicidal activity of plied in the field comprising the concentrate composisome of the organotin compounds of the invention. tion (i.e., active ingredient plus herbicidal adjuvant) and Thus these organotin compounds are particularly usethe carrier. ful in soil sterilization applications. As demonstrated in the examples above, quite different effects can be obtained by modifying the method of Example 7 use of the herbicidal composition of this invention. Thus, In this example, the contact herbicidal activity of some unusual specificity can be achieved at lower levels of apof the organotin compounds of this invention was dete plication whereas at higher levels of application a more mined in. greenho se tests. The organotin compound general herbicidal effect or soil sterilization takes lace. to be tested was applied in spray form to 21-day old Therefore, an essential part of this invention is the formuspecimens of the same grasses and broadleaf plants as lation of the herbicidal composition so as to permit a used in the pre-emergent tests described in Example 6. uniform predetermined application of the composition to The Same number 0f seeds 05 the Same Plants Used in the plant environment to produce the desired effect. Example 6 Wer planted in the 9 /2 X 5% X alumi- Herbicidal adjttvants useful in preparing the concennum pans arranged in the same manner with a soybean trate compositions and, therefore, the herbicidal toxic ant seed in diagonal corners as described in Example 6. compositions applied to the soil or plants, include par- Afiflr the Plants were y h aluminum pan ticulate soil or liquid extending agents such as solvents was sprayed with 6 ml. of a 0.5% concentration soluor diluents within which the active ingredient is dissolved tion of the candidate chemical, corresponding to a rate or suspended, wetting or emulsifying agents which serve of approximately 9 lbs. per acre. This herbicidal soluin providing uniform dispersions or solutions of the action was prepared from 1.5 ml., of a 2% solution of tive ingredient in the extending agents, and adhesive agents the candidate compound in acetone, 0.2 ml. of a 3:1 or spreading agents which improve the contact of the cyclohexanone-emulsifying agent mix, and sufficient waactive ingredient with the soil or plant surfaces. All ter to make a volume of 6 ml. The emulsifying agent herbicidal compositions of this invention include at least one of the above types of herbicidal adjuvants and usually include an extending agent and a wetting or emulsifying agent.

The active ingredient need not be dissolved in the extending agent but may merely be dispersed or suspended in the extending agent as a suspension or emulsion. Also, the organotin compounds may first be dissolved in a suitable organic solvent and the organic solution of the active ingredient then incorporated in Water or an aqueous extending agent to form a heterogeneous dispersion. Examples of some suitable organic solvents for use as extending agents include hexane, benzene, toluene, acetone, cyclohexanone, methylethylketone, isopropanol, butanediol, methanol, diacetone alcohol, xylene, dioxane, isopropyl ether, ethylene dichloride, tetrachloroethane, hydrogenated naphthalene, solvent naphtha, petroleum fractions (e.g., those boiling almost entirely under 400 F. at atmospheric pressure and having flash points above about 80 F., particularly kerosene), and the like.

Solid extending agents in the form of particulate solids are very useful in the practice of the present invention. In using this type of extending agent, the active ingredient is either adsorbed or dispersed on or in the finely-divided solid material. Preferably the solid extending agents are not hygroscopic but are materials which render the composition permanently dry and free flowing. Suitable solid extending agents include the natural clays, such as china clays, the bentonites and the attapulgites; other minerals in natural state, such as talc, pyrophyillite, quartz, diatomaceous earth, Fullers earth, chalk, rock phosphate, kaolin, kieselguhr, volcanic ash, salt and sulfur; the chemically modified minerals, such as acid-washed bentonite, precipitated calcium phosphate, precipitated calcium carbonate, calcined magnesia, and colloidal silica; and other solid materials such as powdered cork, powdered wood, and powdered pecan or walnut shells. These materials are used in finelydivided form, at least in a size range of 20-40 mesh and preferably in much finer size.

The particulate solid concentrate compositions are applied to the soil by admixture at the time of application with a particulate solid carrier material. If desired, this concentrate composition can also be applied as a wettable powder using a liquid carrier material. When used by this method, a wetting agent or surface active agent is added to the concentrate composition in order to render the particulate solid extending agent wettable by water to obtain a stable aqueous dispersion or suspension suitable for use as a spray. Also, the extending agent applied as a wettable powder is used in very finely-divided form, preferably in a size as small as 100 mesh or smaller.

The surface active agent, that is the wetting, emulsifying, or dispersion agent, used in the herbicidal composition of this invention to serve in providing uniform dispersions of all formulation components of both liquid and dust types in both the concentrate compositions and the toxicant compositions applied, may be either anionic, cationic, or non-ionic types, including mixtures thereof. Suitable surface active agents are the organic surface active agents capable of lowering the surface tension of water and include the conventional soaps, such as the water-soluble salts of long-chain carboxylic acids; the amino soaps, such as the amine salts of long-chain carboxylic acids; the sulfonated animal, vegetable, and mineral oils; quaternary salts of high molecular weight acids; resin soaps, such as salts of abietic acid; sulfuric acid salts of high molecular weight organic compounds; algin soaps; ethylene oxide condens'ated with fatty acids, alkyl phenols and mercaptans; and other simple and polymeric compositions having both hydrophilic and hydrophobic functions.

The herbicidal concentrate compositions of this invention ordinarily have the active ingredient and the surface active agent present in higher concentrations than the toxicant compositions applied in the field so that upon dilution with the liquid or solid carrier, compositions containing optimum proportions of active ingredient and surface active agent are prepared to obtain uniform distribution and to maintain the active ingredient in a form which enables the prompt assimilation by the plant.

The liquid concentrate compositions of this invention preferably comprise 5% to by weight of the active ingredient and the remainder the herbicidal adjuvant, which may be solely liquid extending agent or surface active agent (including adhesive agent), but preferably is a combination of liquid extending agent and surface active agent. Preferably, the surface active agent comprises from 0.1% to 15% by weight of the total concentrate composition. The remainder of the composition is the liquid extending agent.

Use of the surface active agent is necessary in the formulation of liquid concentrate compositions in order to obtain a composition containing a sufficient concentration of the difficultly soluble organotin compounds in the liquid extending agent. However, the liquid extending agent must be selected not only on the basis of the amount of the organotin compound dissolved but also upon the basis of the solution temperature of the total composition. Thus, in some formulations, a particular combination of solvents give a sulficiently low solvent temperature but the amount of the organotin compound dissolved or dispersed in the mixture is insufficient and a suitable surface active agent must be selected in order that more organotin compound can be dispersed in the composition. Preferably, the concentrate composition has a solution temperature below 0 C. although compositions having solution temperatures as high as 20 C. can be used.

The concentration of organotin compound in the particulate solid or dust concentrate composition of this invention may vary over wide ranges depending upon the nature of the solid extending agent and the intended use of the composition. Applied at very low rates in order to obtain selectivity, the concentration of the active ingredient in the dust composition may be very low and may comprise as little as l% or less by wt. of the total dust composition. By contrast, when the dust composition is to be used for soil sterilization, it may be desirable to have a very high concentration of active ingredient and for such use the active ingredient may comprise as much as 5% to 98% by wt. of the total composition. The remainder of the composition is the herbicidal adjuvant which is usually only the particulate solid extending agent. Thus, the surface active agent is not usually required in dust concentrate compositions although it can be used if desired. However, if the dust concentrate composition is to be applied as a wettable powder, surface active agent must be added to the concentrate composition and ordinarily the amount of surface active agent will be in the range of 0.1% to 15 by wt. of the composition.

The carrier material, used for the uniform distribution of the organotin compound in a herbicidally effective amount to inhibit the growth of either all or selected plants, may be either a liquid or a particulate solid material. The liquid and solid extending agents used to prepare the concentrate composition may also be used as the carrier; however, the use of these materials as a carrier is often not economical. Therefore, water is the preferred liquid carrier, both for use with the liquid concentrate composition and the wettable powder concentrate. Suitable particulate solid carriers include the particulate extending agents noted above as Well as the solid fertilizers such as ammonium nitrate, urea, and superphosphate, as well as other materials in which plant organisms may take root and grow, such as compost, manure, humus, sand and the like.

The liquid and dust concentrate compositions of this invention can also contain other additaments such as fertilizer and pesticides. Also, these additaments may be used as, or'in combination with, the carrier materials.

The herbicidal compositions of this invention are applied to the plant systems in the conventional manner. Thus, the dust and liquid compositions may be applied to the foliage of growing plants by the use of power-dusters, broom and hand spr-ayers, and spray-dusters. The compositions can also be very suitably applied from airplanes as a dust or a spray because the herbicidal compositions of this invention are effective in very low dosages. In order to prevent growth of germinating seeds or emerging in EXAMPLE 8 For evaluation of the bacteriostatic and fugistatic effects of these new compounds, several of these compounds were tested. These compounds were mixed in predetermined concentrations with hot sterile agar which was subsequently poured into Petri dishes, cooled, and allowed to harden. Nutrient agar containing the test compounds was then inoculated with the bacteria Staphylococcus aureus and Salmonella typlzosa and incubated for two days at 37 C.; and Sabourauds dextrose agar containing the test compounds was inoculated with the fungus organism Aspargillus niger, and incubated for five days at 27 C. The results of these tests are reported in Table 3 below.

Table 3 Staphylococcus aureus, Salmonella typhosa, Aspergz'llus niger, Compound ppm. ppm. p.p.m.

The product of- Example 2 a a a a a i i 1 a a a a Example 3... a a a a a i i 1 a a a i Example 4 a a a a 1 1 i 1 a a a a a active. i inactive.

seedlings, the dust and liquid compositions are applied to the soil according to conventional methods, and, preferably, distributed in the soil to a depth of at least /2 inch below the soil surface. It is not absolutely necessary that the herbicidal compositions be admixed With the soil particles and these compositions can be applied merely by spraying or sprinkling 'onto the surface of the soil. The herbicidal compositions of this invention can also be applied by addition to irrigation water supplied to the field to be treated. This method of application permits the penetration of the compositions into the soil as the water is obsorbed therein. Dust compositions sprinkled on the surface of the soil can be distributed below the surface of the soil by the usual discing, dragging, or mixing opera- 5 tions.

The application of a growth-inhibiting amount or toxic amount of the organotin compound to the plant system is essential in the practice of the present invention. The exact dosage to be applied is dependent not only upon the specific organotin compound but also upon the particular a plant species to be controlled and the stage of growth thereof as well as the part of the plant to be contacted with the toxicant. In non-selective foliage treatments, the herbicidal compositions of this invention are usually applied at a rate sufiicient to obtain from 5 to lbs. of organotin compound per acre but lower or higher rates might be applied in some cases. In non-selective preemergent treatments, these herbicidal compositions are usually applied at a somewhat lower rate than in foliage treatments but at a rate which is ordinarily within the same general range; that is, at a rate in the range of 1 to 25 lbs. per acre. In selective pre-emergent applications to the soil, a dosage of from 0.5 to 5 lbs. of active ingredient per acre is usually employed but lower or higher rates may be necessary in some instances. It is believed that one skilled in the art can readily determine from this disclosure, including the examples, the optimum rate to be applied in any particular case.

The essential active ingredient of the herbicidal compositions of this invention is the organotin compound disclosed in this specification. Of course, one skilled in the art will understand that mixtures of various organotin compounds can also be used. 7*

It is noted from an examination of the data in Table 3 that the organotin compounds of the invention are very active bacteriostats and fungistats; that concentrations in some cases were as low as one part per million of the test compounds. Usually these novel compounds will be applied as bacteriostats or fungistats at concentrations in the range of 0.0001% to 1.0%, preferably 0.001% to 0.1% suspended, dispersed or dissolved in inert carriers.

The new compounds of this invention may be applied to microorganisms (bacteria and fungi), the growth of which it is wished to inhibit, or they may be compounded in emulsions or in other forms in a similar manner as described for compounding the organotin compounds as herbicides.

What is claimed is:

1. A method of inhibiting the growth of microorganisms comprising applying to said microorganisms a sulficient amount to inhibit said growth of an organotin compound of the formula RRR"SnO-XOY, wherein R, R and R" are hydrocarbon having not more than 18 carbon atoms, X is selected from the class consisting of aromatic hydrocarbon and aromatic-ring halogenated derivatives thereof having not more than 25 carbon atoms, and Y is a RRR"Sn group wherein R, R and R" are as defined hereinabove.

2. A method of inhibiting the growth of microorganisms comprising applying to said microorganisms a suflicient amount to inhibit said growth of an organotin compound of the formula 1 l 1 2 4. A method of inhibiting the growth of microorgan- References Cited by the Examiner isms comprising applying to said microorganisms a sufii- UNITED STATES PATENTS cient amount to inhibit said growth of an organotin com- Pound of the formula 3,099,668 8/1960 Zwelgle 167-30 01 c1 5 OTHER REFERENCES I I Chemical Reviews, October 1960, pages 494, 495, and

5 5 JULIAN s. LEvrrT, Primary Examiner. 

1. A METHOD OF INHIBITING THE GROWTH OF MICROORGANISMS COMPRISING APPLYING TO SAID MICROORGANISMS A SUFFICIENT AMOUNT TO INHIBIT SAID GROWTH OF AN ORGANOTIN COMPOUND OF THE FORMULA RR''R"SNO-X-OY, WHEREIN R, R'' AND R" ARE HYDROCARBON HAVING NOT MORE THAN 18 CARBON ATOMS, X IS SELECTED FROM THE CLASS CONSISTING OF AROMATIC HYDROCARBON AND AROMATIC-RING HALOGENATED DERIVATIVES THEREOF HAVING NOT MORE THAN 25 CARBON ATOMS, AND Y IS A RR''R"SN GROUP WHEREIN R, R'' AND R" ARE AS DEFINED HEREINABOVE. 